Hi, I purchased a shortened shotgun barrel without a rib from ebay that had a boogerd hacksaw job. Barrel is about 20" so length is fine. I have squared the muzzle with my 5" disk sander and now I need to install a bead. I've picked up a centering V shaped jig at harbor freight for my drill press and ordered a Mossberg plain barrel front sight and 5-40 tap + majic tap fluid. I'm going to build a jig to hold everything steady in the drill press and got an automatic center punch to help keep the drill from walking around when I start drilling metal. The one thing I haven't lined up yet is the drill bit. What size hole should I make when my drill press is set up? Should I do this in two step or just drill the correct diameter hole the first time? I'd like to keep the bead as square to the action as possible so the gun points right. Hope to get some experienced advice. Good news is if I booger the job the first time I can still cut back a bit and retry. I do hope to do it right the first time.